A technique of exploring for resources such as petroleum oil, gas, or a mineral vein using a vibration sensor is known. In this technique, a plurality of vibration sensors are provided, and the presence or absence or a position of resources is specified such that a vibrational wave is generated by a vibration exciter or blasting, and a vibrational wave reflected against resources such as petroleum oil buried underground is detected by the vibration sensors.
For example, a micro electro mechanical systems (MEMS) sensor which is an acceleration sensor is used as the vibration sensor. Since resources are buried deep in the group, and there is a restriction to energy of the vibrational wave generated by the vibration exciter or the like, it is necessary to increase sensitivity of the sensor in order to perform the exploration with a high degree of accuracy.
As a document stating a sensor detection circuit according to a related art, there are Patent Document 1 (U.S. Pat. No. 6,497,149) and Patent Document 2 (U.S. Pat. No. 5,852,242).